[Mesa-dev] [PATCH 2/2] nvc0: reduce overhead from always marking images dirty

[Ilia Mirkin]

We would revalidate images when anything was touched at all. Which is
unfortunate, since the state tracker does not use CSO's to reduce the
workload. So instead implement a protocol to ensure that something has
changed before revalidating all the images.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: "12.0" <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/nouveau/nvc0/nvc0_state.c | 41 +++++++++++++++++++++------
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
index 6cdc007..c05289b 100644
--- a/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
+++ b/src/gallium/drivers/nouveau/nvc0/nvc0_state.c
@@ -1231,36 +1231,58 @@ nvc0_set_compute_resources(struct pipe_context *pipe,
    nvc0_context(pipe)->dirty_cp |= NVC0_NEW_CP_SURFACES;
 }
 
-static void
+static bool
 nvc0_bind_images_range(struct nvc0_context *nvc0, const unsigned s,
                        unsigned start, unsigned nr,
                        struct pipe_image_view *pimages)
 {
    const unsigned end = start + nr;
-   const unsigned mask = ((1 << nr) - 1) << start;
+   unsigned mask = 0;
    unsigned i;
 
    assert(s < 6);
 
    if (pimages) {
       for (i = start; i < end; ++i) {
+         struct pipe_image_view *img = &nvc0->images[s][i];
          const unsigned p = i - start;
+
+         if (img->resource == pimages[p].resource &&
+             img->format == pimages[p].format &&
+             img->access == pimages[p].access) {
+            if (img->resource->target == PIPE_BUFFER &&
+                img->u.buf.first_element == pimages[p].u.buf.first_element &&
+                img->u.buf.last_element == pimages[p].u.buf.last_element)
+               continue;
+            if (img->resource->target != PIPE_BUFFER &&
+                img->u.tex.first_layer == pimages[p].u.tex.first_layer &&
+                img->u.tex.last_layer == pimages[p].u.tex.last_layer &&
+                img->u.tex.level == pimages[p].u.tex.level)
+               continue;
+         }
+
+         mask |= (1 << i);
          if (pimages[p].resource)
             nvc0->images_valid[s] |= (1 << i);
          else
             nvc0->images_valid[s] &= ~(1 << i);
 
-         nvc0->images[s][i].format = pimages[p].format;
-         nvc0->images[s][i].access = pimages[p].access;
+         img->format = pimages[p].format;
+         img->access = pimages[p].access;
          if (pimages[p].resource->target == PIPE_BUFFER)
-            nvc0->images[s][i].u.buf = pimages[p].u.buf;
+            img->u.buf = pimages[p].u.buf;
          else
-            nvc0->images[s][i].u.tex = pimages[p].u.tex;
+            img->u.tex = pimages[p].u.tex;
 
          pipe_resource_reference(
-               &nvc0->images[s][i].resource, pimages[p].resource);
+               &img->resource, pimages[p].resource);
       }
+      if (!mask)
+         return false;
    } else {
+      mask = ((1 << nr) - 1) << start;
+      if (!(nvc0->images_valid[s] & mask))
+         return false;
       for (i = start; i < end; ++i)
          pipe_resource_reference(&nvc0->images[s][i].resource, NULL);
       nvc0->images_valid[s] &= ~mask;
@@ -1271,6 +1293,8 @@ nvc0_bind_images_range(struct nvc0_context *nvc0, const unsigned s,
       nouveau_bufctx_reset(nvc0->bufctx_cp, NVC0_BIND_CP_SUF);
    else
       nouveau_bufctx_reset(nvc0->bufctx_3d, NVC0_BIND_3D_SUF);
+
+   return true;
 }
 
 static void
@@ -1279,7 +1303,8 @@ nvc0_set_shader_images(struct pipe_context *pipe, unsigned shader,
                        struct pipe_image_view *images)
 {
    const unsigned s = nvc0_shader_stage(shader);
-   nvc0_bind_images_range(nvc0_context(pipe), s, start, nr, images);
+   if (!nvc0_bind_images_range(nvc0_context(pipe), s, start, nr, images))
+      return;
 
    if (s == 5)
       nvc0_context(pipe)->dirty_cp |= NVC0_NEW_CP_SURFACES;
-- 
2.7.3